Insulating speaker support



FIG. 1 is a perspective view of an insulating speaker support showing my new design;

FIG. 2 is a front elevational view thereof. The left, rear and right elevational views, being identical thereto, are not shown;

FIG. 3 is a top plan view thereof; and

FIG. 4 is a bottom plan view thereof. 

The ornamental design for an insulating speaker support, substantially as shown and described. 